Functions are not removed even when made internal by
DXILFinalizeLinkage. The removal code is called from alwaysinliner and
globalopt, which are invoked too early to remove functions made internal
by this pass.
This adds a check similar to that in alwaysinliner that removes
trivially dead functions after being marked internal. It refactors that
code a bit to make it simpler including reversing what is stored int he
work queue.
Tests both the pass in isolation and the full i0nlining, linkage
finalization and function removal steps.
Fixes#106139
An HLSL function has internal linkage by default unless it is:
1. shader entry point function
2. marked with the `export` keyword
(https://github.com/llvm/llvm-project/issues/92812)
3. patch constant function (not implemented yet)
This PR adds a link-time pass `DXILFinalizeLinkage` that updates the
linkage of functions to make sure only shader entry points and exported
functions are visible from the module (have _program linkage_). All
other functions will be updated to have internal linkage.
Related spec update: microsoft/hlsl-specs#295
Fixes #llvm/llvm-project#92071
In supporting opaque pointers we need to re-materialize typed pointers
in bitcode emission. Because of how the value-enumerator pre-allocates
types and instructions we need to insert some no-op bitcasts in the
places that we'll need bitcasts for the pointer types.
Reviewed By: kuhar
Differential Revision: https://reviews.llvm.org/D122269
